Video with 50 FPS slightly off
It is most probably a problem with blender. You shouldn't have set it to 50 FPS though. You should have gone with 60 FPS. If you still need it in 50 fps, I would say you should render it in frame-by-frame form and then import it to Camtasia 2020 and arrange it in the order you want. Make each frame last 0.02 seconds. Then see, it will probably work. If it still feels a bit rough, you can smoothen it using the tool you have. I am not very sure though, this is my best guess. If you face any issues, please comment. Hope the answer helps.